So here we have the Maximus V Extreme, which is the literally the biggest (eATX form factor) in the Z77 Republic of Gamers family. Although it is not as asthetically dashing as the Red LED heavy Formula we've seen earlier, it is certainly no slouch feature wise and more catered for the extreme subzero overclocker, as we will see in the following sections.
Over at the I/O panel we get a mix of the new and the old.
From the left, we get single-port 10Gb/s Thunderbolt connectivity in the form of a mini-DP connector, followed by a pair of vertically stacked buttons to trigger CMOS reset and the OC Key menu. Eight USB ports (four of them USB 3.0 and one for BIOS flashback) is augmented by a full sized DP/HDMI for the integrated IGP, Gigabit LAN port and standard jacks for integrated 7.1 channel audio.
A legacy PS/2 port is still present on this year 2012 board, which is appreciated by benchmark record chasing users as USB keyboards incur precious CPU interrupts, albeit minicule but every bit matters guys like Andre and Shamino.
Another I/O expansion can be installed to add two more USB 2.0 and one eSATA port.
Thunderbolt functionality is serviced by the Cactus Ridge 2C DSL 3310 host controller, which takes up 4 PCIe 2.0 lanes.
A no-frills Intel 82579V Gigabit PHY is used for networking. Truth be told we would have preferred dual Gigabit LAN or even 10gE since such controllers are now in mass production.
ASMedia's top performing ASM1042 SuperSpeed USB 3.0 controller, with UASP and Fast Charge support adds more ports on top of those from the native Z77 Panther Point USB 3.0.
Unlike the fancier dedicated audio pathing and shielding on the Formula and Gene, the Extreme opted for a more unassuming design based on Realtek's ALC898 codec.
At the other end of the board, we get a fairly reasonable eight onboard SATA ports. Next to them on the left is ASUS's propietary Subzero Sense feature, which accepts two K-type thermocouples, doing away the need for expensive dedicated thermometers.
As seen on most other recent ASUS boards, a ASMedia ASM1061 takes a single PCIe 2.0 lane to enable two more SATA 6Gb/s ports on top of the six from the Z77 PCH.
Moving on to the PCI Express-only slot layout, there are five x16 slots and one x4 slot for expansion (disabled if Thunderbolt is used). When we examine the PCB soldering points behind, we see that the first two red slots are capable of up to x16 operation, while the third, fourth and sixth slot can do up to x8.
To achieve four-way multi-GPU, a PLX8747 multiplexer is used. This 48-lane bridge chip handles 16 PCIe 3.0 signals from the CPU and can be configured for x16+x16 or x8+x8+x8+x8 for the GPUs.
Another interesting feature which will come in handy for multi-GPU operation is the "+3.3v Power Generator" on the PCIe slots. This auxiliary source of power apparently helps the GPU PLL/Vsync stability during extreme overclocking.